• Question: does the climate effect volcanoes?

    Asked by thegreenapple98 to James V on 26 Jun 2012.
    • Photo: James Verdon

      James Verdon answered on 26 Jun 2012:


      Hi greenapple,
      Not that I’m aware of. Volcanoes are controlled by processes deep within the earth which are not really affected by climate.

      The only time I can think of where climate could affect volcanoes is for volcanoes at the poles that are buried under ice sheets. The volcano has to punch its way not just through the crust, but maybe 2 or 3 kilometers of ice as well. Also the extra weight of all the ice can affect the stresses around the volcano, which can affect the eruption. Because the climate controls where the ice sheets are, it can have a small affect on a handful of volcanoes, but not most.

      However, volcanoes can have a strong affect on climate. When large volcanoes erupt, they can eject huge quantities of dust and ash into the atmosphere, blotting out the sun. This reduces global temperatures, and also affects crop productivity, which can lead to famines. This effect can last for several years until all the dust and ash is washed out of the air by rain. The Tambora eruption in 1815 lead to ‘the year without summer’ because of the ash blotting out the sun, and there were lots of famines because crops did not grow well.

      Also, volcanoes can emit a lot of CO2, which affects our climate by causing global warming. On average, volcanoes emit the same amount of CO2 every year, so their effects are quite constant (so we know that current increases in CO2 are caused by humans burning fossil fuels). However, over longer term timescales, CO2 rates from volcanoes can change, changing the climate. For instance, increased volcanic activity during the Cretaceous Period 80 million years ago (when the Dinosaurs were at their peak) helped create much warmer temperatures than we have today.

Comments